package com.sky.aspect;

import com.sky.annotation.AutoFill;
import com.sky.constant.AutoFillConstant;
import com.sky.context.BaseContext;
import com.sky.enumeration.OperationType;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;
import java.time.LocalDateTime;

@Aspect
@Component
@Slf4j
public class AutoFillAspect {
    /**
     * 切入点
     */
    @Pointcut("execution(* com.sky.mapper.*.*(..)) && @annotation(com.sky.annotation.AutoFill)")
    public void autoFillPointCut() {
    }

    /**
     * 前置通知，在通知中进行公共字段的赋值
     */
    @Before("autoFillPointCut()")
    public void autoFill(JoinPoint joinPoint)  {
        log.info("开始公共字段自动填充");

        //获取当前被拦截方法上的数据库操作类型
        MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
        //获取方法上的注解对象
        AutoFill annotation = methodSignature.getMethod().getAnnotation(AutoFill.class);
        //获取数据库操作类型
        OperationType operationType = annotation.value();
        log.info("数据库操作类型：{}", operationType);
        //约定实体对象作为第一个参数
        //获取到当前被拦截的方法参数-->实体对象
        Object[] args = joinPoint.getArgs();
        //防止空指针异常
        if (args == null || args.length == 0) {
            return;
        }
        log.info("实体对象：{}", args);
        Object entity= args[0];
        //准备赋值的数据
        LocalDateTime now = LocalDateTime.now();
        Long currentId = BaseContext.getCurrentId();
        //根据不同的操作类型,对应的属性通过反射来赋值
        //为几个公共字段赋值
        //如果是insert就需要为createTime和updateTime,createBy和updateBy赋值
        //如果是update就需要为updateTime和updateBy赋值
        if (operationType == OperationType.INSERT) {
            try {
                Method setCreateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_TIME, LocalDateTime.class);
                Method setCreateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_USER, Long.class);
                Method setUpdateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_TIME, LocalDateTime.class);
                Method setUpdateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_USER, Long.class);
                //通过反射为对象属性赋值
                setCreateUser.invoke(entity, currentId);
                setCreateTime.invoke(entity, now);
                setUpdateUser.invoke(entity, currentId);
                setUpdateTime.invoke(entity, now);

            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        } else if (operationType == OperationType.UPDATE) {
            try {
                Method setUpdateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_TIME, LocalDateTime.class);
                Method setUpdateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_USER, Long.class);
                setUpdateUser.invoke(entity, currentId);
                setUpdateTime.invoke(entity, now);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    }
}
